Chamber for a blood treatment system, blood tubing system, and blood treatment system

ABSTRACT

The present invention relates to a chamber for a blood treatment system having a blood inlet and a blood outlet, a filter element for air separation which is arranged at the head side with respect to the position of the chamber in the operating state and which can be decoupled from the blood present in the chamber in the operating state by means of a further liquid, to a blood hose system and to a blood treatment system.

The present invention relates to a chamber for a blood treatment system having a blood inlet and a blood outlet, and a filter element for air separation which is arranged at the head side with respect to the position of the chamber in the operating state and which can be decoupled from the blood present in the chamber in the operating state by means of a further liquid, to a blood hose system and to a blood treatment system.

In known hemodialysis systems a venous drip chamber which is a component of the extracorporeal blood circuit is located downstream of a dialysis filter. Said venous drip chamber provides a bubble-free reinfusion of the dialyzed patient blood at this point. The venous drip chamber is usually not completely filled. There is thus a disadvantageous blood-to-air contact here. To avoid an infusion of blood clots, the venous drip chamber is equipped with a clot trap which is as a rule designed as a screen.

A plurality of examples for drip chambers are already known from the prior art.

DE 32 02 582 A1, for instance, shows a drip chamber in which the blood dripping in does not drop directly into the blood level, but rather onto an oblique inner wall to minimize foam formation and thus the risk of a possible hemolysis.

U.S. Pat. No. 5,330,425 describes a plurality of blow-molded drip chambers for dialysis treatment having a specially located injection site.

U.S. Pat. No. 3,834,386 describes a drip chamber having a septum integrated into the cap of the drip chamber.

The blood inlet into the chamber frequently takes place in the state of the art via a corresponding port whose end is above the blood level. A dripping of the blood into the chamber therefore takes place, which brings along the danger of the formation of microbubbles, with such microbubbles not being able to be separated and being able to be led back to the patient without impediment. These microbubbles can moreover cause hemolysis.

A standard drip chamber usually furthermore has an injection port having a hydrophobic septum and has a venting line which is provided with a hydrophobic membrane, in particular a so-called transducer protector (TDP). The venting line can, on the one hand, be guided via a 3-way valve in the interior of the machine to a pressure transducer for the monitoring of the pressure in the venous drip chamber or can, on the other hand, vent the drip chamber via a pressure reducer, such as is the case on the initial filling of the hose system or of the extracorporeal blood circuit.

A venous drip chamber is furthermore known from WO 2007/050211 A2 in which the blood inlet port and the blood outlet port are arranged in the base of the chamber and wherein a dividing wall is located between the blood inlet port and the blood outlet port. A hydrophobic membrane is let into the cap of the chamber to vent the chamber. The chamber is completely filled with saline solution at the start, with the filling taking place via a blood inlet port. When blood is flowing into the chamber in dialysis operation, the displaced saline solution is supplied to the patient. A certain quantity of saline solution remains in the chamber to decouple the hydrophobic membrane from the blood level. The handling of such a drip chamber is often associated with not insignificant effort and considerable care since it has to be ensured that sufficient saline solution remains in the chamber to decouple the hydrophobic membrane from the blood level and to ensure a correct operation of the drip chamber.

It is therefore the object of the present invention to further develop in an advantageous manner a chamber for a blood treatment system of the initially named kind, in particular such that a venous drip chamber is provided which has minimized blood-to-air contact, which also reliably prevents the formation of microbubbles and can moreover be operated simply and reliably.

This object is solved in accordance with the invention by a chamber for a blood treatment system having the features of claim 1. Provision is accordingly made that a chamber for a blood treatment system has a blood inlet and a blood outlet as well as a filter element for air separation which is arranged at the head side with respect to the position of the chamber in the operating state and which can be decoupled from blood present in the chamber in the operating state by means of a further liquid. Provision is further made that the blood inlet is arranged at the head side. The advantage results due to the arrangement of the blood inlet at the head side that the simple handling capability can be maintained with the chamber in accordance with the invention, such as was also already the case with the previous drip chambers. For the blood inlet at the head side allows a simple filling of the chamber with blood. This is in particular of advantage on the initial venting of the drip chamber. The air separation is no longer carried out via a transducer protector due to the filter element for air separation arranged at the head side, but rather directly via a filter membrane which is decoupled from the blood by means of a further liquid so that a so-called clotting of blood at the filter element is prevented.

The chamber moreover advantageously no longer has a venting line. Consequently a wetting or a breakthrough of the advantageously no longer present transducer protector (TDP) can also not occur, whereby the danger of contaminating e.g. the connected dialysis machine is precluded.

A plurality of problems of the current extracorporeal circuit can thus be solved. It is possible to carry out a conversion of the pressure measurement to a non-invasive measurement by means of a pressure dome, for example, with a cessation of the transducer protector problems resulting. The contamination consequences at the machine side associated with the transducer protector furthermore no longer occur since, for example, a replacement of a pressure transducer after a blood contact no longer has to take place. Since there is no air present in the operating state of the chamber, since preferably the lower half is completely filled with blood and the further liquid which decouples the filter element from the blood present in the chamber in the operating state is located above the blood level, there is no direct blood-to-air contact and no stagnation regions in the chamber. The need for clotting inhibitors can thereby be considerably reduced. The formation of microbubbles in the venous chamber can furthermore be prevented.

Provision can be made that the blood outlet is arranged at the base side in the chamber with respect to the position of the chamber in the operating state.

The invention furthermore relates to a chamber for a blood treatment system having the features of claim 3. Provision is accordingly made that a chamber for a blood treatment system has a blood inlet and a blood outlet as well as a filter element for air separation which is arranged at the head side with respect to the position of the chamber in the operating state and which can be decoupled from blood present in the chamber in the operating state by means of a further liquid, with the further liquid being able to be supplied by means of a supply port. The advantage thereby results that the further liquid for the decoupling of the filter element from blood present in the chamber in the operating state can be supplied during operation. Liquid can thus optionally be topped up when some of the decoupling liquid mixes with the blood in the chamber and should thus leave the chamber through the blood outlet in operation.

Provision can be made that the chamber having the features of claim 3 has the characterizing features of claim 1 or claim 2.

Provision can further be made that the chamber having the features of claim 1 or claim 2 has the characterizing features of claim 3.

It is furthermore conceivable that the further liquid can be supplied continuously or can be supplied at predefined time intervals and/or that the filter element includes a hydrophobic filter membrane or is formed by such. The advantage thereby results that it is ensured during operation that the filter element does not clog. It is in particular of advantage on the continuous supply of liquid that a continuous air separation is ensured due to the continuously onflowed hydrophobic membrane. It is hereby effectively avoided that blood components can collect at the hydrophobic membrane. The same effect can also be achieved in that the further liquid is supplied at predefined time intervals, for instance in a clocked manner. Air separation from the blood can then take place at the interface between the blood and the further liquid. The air rising out of the blood passes over the interface between blood and the further liquid and then rises upwardly. It can there escape via the hydrophobic filter. A mixing of blood and the further liquid can take place at the liquid boundary between the two substances, which is equivalent, for example, to a bolus addition on a hemofiltration or hemodiafiltration. In order advantageously to maintain the substituate level or the liquid level of the further liquid around the hydrophobic membrane, the substituate must be permanently topped up. This is preferably done via the setting of a substituate flow via the supply port and corresponding means for substituate control of e.g. a dialysis machine. In this process, the substituate introduced does not come into contact with air, unlike with drip chambers in which the substituate is dripped in via an infusion port. This avoids the formation of microbubbles and their infusion into the patient. The chamber is, for example, also suitable for hemodialysis when the introduced substituate quantity is small.

Provision can furthermore be made that the supply port has a check valve and/or a means preventing a backflow. The advantage hereby results that an inflow of blood into the supply port can be effectively prevented.

Provision can furthermore be made that the chamber has an infusion port and/or, in front of the blood inlet, a screen. The screen can, for example, be a so-called clot trap. It is possible in a simple manner by the infusion port to connect one or more infusions to the chamber.

It is furthermore conceivable that the chamber has a substantially cylindrical base body and the chamber is designed so eccentrically and/or flared in its upper end that the blood entering into the chamber via the blood inlet can be dripped onto an oblique wall formed thereby, with the blood inlet being arranged eccentrically and parallel to the center axis of the chamber so that the blood can be supplied to the chamber in an off-center manner. The advantage hereby results that the occurrence of microbubbles is further prevented since, on the one hand, foam formation can be effectively prevented on the initial filling. On the other hand, the path through the air of a blood droplet up to the impact on the wall is hereby reduced on the initial filling.

Provision can in particular be made that the blood inlet in the operating state is below the blood level adopted in operation with a filled chamber. This means that the outlet opening of the blood inlet is located beneath the blood level in the chamber and the blood supplied to the chamber can enter directly and without diversions or air contact into the blood compartment in the chamber.

Provision can furthermore be made that the outlet of the supply port for the substituate is arranged directly next to the filter element at the head side. The advantage thereby results that a simple and secure flow pattern around the filter element can be ensured.

Provision can moreover be made that the chamber is a venous drip chamber of a blood hose system, in particular of a blood hose system for dialysis.

It is furthermore conceivable that the liquid which can be supplied via the supply port is a filtered and pyrogen-free liquid, in particular a pyrogen-free and filtered dialysate and/or a saline solution.

The present invention furthermore relates to a blood hose system having the features of claim 13. Provision is accordingly made that a blood hose system is provided with at least one chamber in accordance with one of the claims 1 to 12.

The invention furthermore relates to a blood treatment system having the features of claim 14. Provision is accordingly made that a blood treatment system is provided with at least one chamber in accordance with one of the claims 1 to 12 and/or a blood hose system in accordance with claim 13.

Provision can be made that the blood treatment system is a dialysis machine and that the liquid which can be supplied via the supply port is filtered and pyrogen-free dialysate which is provided and/or treated by the dialysis machine.

Further details and advantages will now be explained in more detail with reference to an embodiment shown in the drawing. There are shown:

FIG. 1: a schematic representation of a chamber in accordance with the invention for a blood treatment system; and

FIG. 2: a further schematic representation of the chamber shown in FIG. 1.

FIG. 1 shows in a schematic representation the chamber 10 in accordance with the invention which is designed as a venous drip chamber 10 of a venous part of an extracorporeal blood hose system for a dialysis machine. In this respect, the venous drip chamber 10 has a cylindrical base body 12 with a smaller diameter d1 in the lower region than is the case in the upper region 16 which is likewise designed as a cylinder. The regions 12 and 16 are in this respect connected by an oblique peripheral slanted wall 14. The chamber 10 is thereby designed in such a flared manner in its upper end that the blood entering into the chamber 10 via the blood inlet 22 can be dripped onto a slanted wall 14.

The blood inlet 22 is in this respect arranged eccentrically and parallel to the center axis of the chamber 10 so that the blood can be supplied to the chamber in an off-center manner. The blood inlet 22 is in this respect a rigid tubular piece 22 whose outlet opening, as shown in FIG. 2, is located beneath the blood level B adopted in the chamber 10 in the operating state. The blood inlet tubular piece 22 in this respect contacts the inner side of the wall of the upper region 16 which has a diameter d2. The diameter d2 is in this respect larger than the diameter d1, whereby it is ensured that the blood exiting the outlet opening 23 initially on the filling of the chamber 10 is dripped onto the slanted wall 14 and not onto the blood already present in the lower region 12. The dialysed blood entering into the chamber 10 leaves the chamber 10 after passing through the clot trap 40 which is arranged in front of the blood outlet 24 at the base side.

A dome-like molding 19 is provided centrally in the roof 18 of the chamber and the filter element 26 designed as a hydrophobic membrane 26 is arranged in its upper part. The air separation from the chamber is achieved via the filter element 26. This filter element 26 can optionally be a double membrane or have an additional filter such as a Porex filter, which can, for example, be of advantage with condensation effects.

In a preferred embodiment of the present invention, the filter element 26 is located above the outlet opening 23, and particularly preferred at the highest position in the chamber 10.

To ensure the continuous air separation over the total dialysis duration, the hydrophobic membrane 26 is washed by dialyzing liquid over the total dialysis duration which is supplied to the chamber via the supply port 28 with the check valve 30. The check valve 30 prevents blood from being able to enter into the supply line 28. The supply line 28 is connected to the dialysate line of the dialysis machine so that the pyrogen-free and filtered dialysate treated in the dialysis machine can be supplied continuously into the chamber during the dialysis duration via the supply port 28 so that the filter element 26 is constantly flushed.

The liquid distribution shown in FIG. 2 is adopted in this process, with the gas, in particular air, present in the blood B rising over the boundary surface S into the dialysate D or substituate D and moving from there to the air separator 26.

The chamber furthermore has an infusion port 32 which has a septum 34 or a luer connector 34. 

1. A chamber (10) for a blood treatment system having a blood inlet (22) and a blood outlet (24), characterized in that a filter element (26) for air separation is provided which is arranged at the head side with respect to the position of the chamber in the operating state and which can be decoupled from the blood (B) present in the chamber (10) by a further liquid (D) in the operating state, with the blood inlet being arranged at the head side.
 2. A chamber (10) in accordance with claim 1, characterized in that the blood outlet (24) is arranged in the chamber (10) at the base side with respect to the position of the chamber (10) in the operating state.
 3. A chamber (10) for a blood treatment system having a blood inlet (22) and a blood outlet (24), characterized in that, a filter element (26) for air separation is provided which is arranged at the head side with respect to the position of the chamber (10) in the operating state and which can be decoupled from the blood (B) present in the chamber (10) by a further liquid (D) in the operating state, with the further liquid (D) being able to be supplied by means of a supply port (28).
 4. A chamber (10) for a blood treatment system having a blood inlet (22) and a blood outlet (24) and having a filter element (26) for air separation which is arranged at the head side with respect to the position of the chamber (10) in the operating state and which can be decoupled from the blood (B) present in the chamber (10) by a further liquid (D) in the operating state, with the further liquid (D) being able to be supplied by means of a supply port (28), characterized in that the chamber (10) has the characterizing feature of claim
 1. 5. A chamber (10) in accordance with claim 1, characterized in that a further liquid (D) is able to be supplied by means of a supply port (28).
 6. A chamber (10) in accordance with claim 1, characterized in that the further liquid (D) can be supplied continuously or can be supplied at predefined time intervals; and/or in that the filter element (26) includes a hydrophobic filter membrane or is formed by it.
 7. A chamber (/10) in accordance with claim 3, characterized in that the supply port (28) has a check valve (30) and/or a means preventing backflow (30).
 8. A chamber (10) in accordance with claim 1, characterized in that the chamber (10) has an infusion port (22) and/or has a screen means (40) in front of the blood outlet (24).
 9. A chamber (10) in accordance with claim 1, characterized in that the chamber (10) has a substantially cylindrical base body and the chamber (10) is formed eccentrically and/or in a flared manner in its upper end such that the blood entering into the chamber (10) via the blood inlet (22) can be dripped onto an oblique wall (14) formed thereby, with the blood inlet (22) being arranged eccentrically and parallel to the center axis of the chamber (10) so that the blood can be supplied to the chamber (10) in an off-center manner; and/or in that the outlet opening (23) of the blood inlet (22) is located beneath the blood level (S) adopted in the chamber (10) in operation.
 10. A chamber (10) in accordance with claim 3, characterized in that the outlet of the supply port (28) is arranged directly next to the filter element (26) at the head side.
 11. A chamber in accordance with claim 1, characterized in that the chamber (10) is a venous drip chamber (10) of a blood hose system, in particular of a blood hose system for dialysis.
 12. A chamber (10) in accordance with claim 1, characterized in that the liquid (D) which can be supplied via the supply port (28) is a filtered and pyrogen-free liquid, in particular a pyrogen-free and filtered dialysate and/or is a saline solution.
 13. A blood hose system having at least one chamber (10) in accordance with claim
 1. 14. A blood treatment system for the reception of at least one chamber (10) in accordance with claim
 1. 15. A blood treatment system in accordance with claim 14, characterized in that the blood treatment system is a dialysis machine; and in that the liquid (D) which can be supplied via the supply port (28) is a filtered and pyrogen-free dialysate which is provided and/or treated by the dialysis machine. 